Welded bulb and cap



Aug. 12, 1947. M. F. WEIDA WELDED BULB AND CAP Filed May 16, 1944 2 c w fi h W 97/47/19 IN VEN TOR. if; F 14/ /49 Patented Aug. 12, 1947 UNITED STATES PATENT OFFICE WELDED BULB AND GAP Millard F. Weida, St. Louis, Mo, assignor, by

'mesiie assignments, to KnappaMonarch Company, St. Louis, Me, a corporation of Delaware Application May 16, 1944, Serial No. 535,893

N 2 Claims. 1

My present invention relates to a siphon bulb structure and a cap therefor, which cap is inte'gral with respect to the bulb.

One object of the invention is to provide abulb for enclosing a charge of matter in a leak-proof manner even though the contents are under high pressure, the structure being such that the charge in the bulb is retained indefinitely without leakage.

1 Another object is to provide a siphon bulb structure and a cap which may be welded thereto, whereby the bulb and cap are formed into a homogeneous enclosure for compressed gas or the like such as CO2 for siphon bottles, life belts and the like.

Another object is to provide a bulb having a neck so formed that it may be welded with respect to a cap for the neck between electrodes by a projection or spot welding method.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my welded bulb and cap whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, wherein:

Fig. 1 is a full size perspective View of a welded bulb and cap embodying my present invention.

Fig. 2 is an enlarged sectional view of the upper end of the bulb and cap showing them separated from each other.

Fig. 3 is a sectional view of the bulb and cap showing them engaged with each other and positioned between electrodes.

Fig. 4 is a further enlarged sectional view of the bulb neck and cap showing the two welded together; and,

Fig. 5 is a similar sectional View showing a weld produced by a longer welding operation than that shown in Fig. 4 and extending the welded joint for the purpose of strengthening it for greater pressures than used in the bulb of Fig. 4.

On the accompanying drawing, I have used the reference numeral ill to indicate an ordinary siphon bulb, although my invention may be applied to larger bulbs if desired. The bulb in has a neck I 2 and on this neck is a cap C having a wall l4 and a top l6.

As shown in Fig. 2, the neck I2 is chamfered around its upper end as indicated at l8 and this results in a relatively narrow tubular end projecting above the thick part of the neck I2. As shown in Fig. 3, when the cap top i 6 engages the tubular end 20, there is a relatively narrow ring of contact. This ring is considered a projec- 2 tion and enters into a projection welding operation as distinguished from butt welding, as will hereinafter appear.

While the cap C is merely resting'on the bulb i2, the two are enclosed in a pressure chamber, not shown in this application as it forms no part of my present invention. The gas with which the bulb is to be charged is then introduced into this chamber and charges the bulb, the wall l4 serving as a guide to prevent the cap from getting out of place, after which pressure is applied on the cap and bulb by moving either an electrode 22 upwardly or an electrode 24 downwardly.

The electrodes 22 and 24 are then energized to effect a projection weld that results in the metal of the end 26 being projected into the metal of the cap l4 and becoming an integral part of the top l6 thereof as shown in Fig. 4. The cap wall l4, it will be noted, is slightly larger than the neck [2 so that when placed on the neck it does not cause an electrical short from the neck to the cap. The gas in the bulb is thus effectively enclosed against leakage and will be retained by the welded joint indefinitely. The electrodes may then be released and the bulb removed.

Fig. 4 illustrates a flash weld caused by only momentarily passing electric current through the electrodes 22 and 24, whereas if the pressure of the electrodes is maintained and a longer current flow is utilized, the welded area will increase in extent as shown for instance in Fig. 5. This may be desirable in case the pressure within the bulb is extremely high.

The arrangement of my bulb and cap and the position of the welded joint produce a welded bulb and cap structure that eliminates an exposed outside flash and the necessity of trimming it off. Any flashthat results from the weld is entirely enclosed Within the cap where it requires no attention and does not present an external ragged edge. At the same time a very effective seal of integral character is provided with absolute assurance, that leaks will not develop because the parts are integral instead of separate with a gasket between them as is usually done in the capping of siphon bulbs. Also the cap C can be made to standard outside dimensions so as to fit against the usual gasket adjacent the piercing pin of a V siphon bottle or other appliances which would require this type of bulb.

My structure also is adaptable for salvage of the bulb after use. The punctured cap can be machined off in an automatic screw machine and 1. In a welded bulb and .cap structure, a bulb having a neck provided with an exteriorly chamfered edge presenting a relatively narrow tubular end, and a cup-shaped cap having a side wall loosely fitting around the outside of said neck and a top wall engaging said narrow tubular end and welded thereto to form said=bulb and cap into an integral structure with theweld enclosed within said side wall of said cap, the interior surface of said cap being substantially straight axially ofthe cap.

2, In a welded bulb and cap structure, a bulb having a neck presenting a relatively narrow tubular upper edge of less diameter than the exterior diameter of said neck, and a cap formed of 4 sheet metal and having a disc-like top member and a flange depending from the peripheral edge thereof, said flange fitting around the outside of said neck, and said top member engaging said narrow tubular edge and welded thereto to form said bulb and cap into anintegral structure with the weld enclosed within said flange and extend-' ing into the space provided by reason of said tubular upper edge being of less diameter than the exterior diameter of said neck.

- MILLARD F. WEIDA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED. STATES PATENTS Number Name Date 2,061,641 Tinkham Nov. 24, 1936 2,352,754 Anderson et a1 July 4, 1944 1,691,778 McDonald NOV. 13, 1928 1,648,026 Murray Nov. 8, 1927 2,265,561 Hoern Dec. 9, 1941 1,968,976 Van Halteren Aug. 7, 1934 l Smith May 29, 1900 

